| 三峡库区万州段消落带植被及土壤理化特征分析 |
| Characteristics of Vegetation and Soil in the Water Level Fluctuation Zone of the Wanzhou Region of Three Gorges Reservoir |
| 投稿时间：2015-12-07 修订日期：2016-05-23 |
| DOI：10.15928/j.1674-3075.2016.02.004 |
| 中文关键词:三峡水库 消落带 植物群落 重要值 土壤性质 |
| 英文关键词:Three Gorges Reservoir water level fluctuation zone plant community importance value soil properties |
| 基金项目:国家水体污染控制与治理重大专项（2013ZX07104-004）；三峡后续工作科研项目（2013HXKY2-3） |
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| 中文摘要: |
| 水文节律是河岸带植物群落演替的主要驱动因子，受水文节律影响的土壤理化特性也有可能逐渐改变周边植被，为了探究周期性淹没对三峡水库消落带植物群落及其生境状况的影响，2015年8月至9月，以三峡水库腹地万州段消落带为研究区域，调查分析了8个样地、24个样带、96个样方的消落带植被及土壤理化特征。结果表明，在三峡库区万州段消落带共调查到维管植物22科、47属、51种，其中禾本科、菊科、蓼科和莎草科的种类数较多；植物群落组成以草本植物为主，其中一年生和多年生草本植物分别占58.8%和27.5%。高程不同，群落优势种有差异，145~155 m及156~165 m区域优势度较高的物种相近，为狗牙根（Cynodon dactylon）、光头稗（Echinochloa crusgalli var. mitis）和醴肠（Eclipta prostrata）；高程166~175 m区域优势度较高的物种为鬼针草（Bidens pilosa）和狗尾草（Setaria viridis）和狗牙根；高程156～166 m区域植物鲜重均值最高，为（2199.1±863.9）g/m2；高程166~175 m区域Shannon-Wiener 多样性指数和Pielou 均匀度指数的均值最高，分别为（2.00±0.30）和（0.85±0.06）。随着坡度等级增加，植物鲜重和盖度呈递减趋势，物种数在6~15°区域最高。长江左岸消落带植物鲜重、高度、Shannon-Wiener和Pielou 指数高于右岸。消落带土壤理化性质具有较高的空间异质性，土壤容重、pH、有机质、全氮、有效氮、全磷、有效磷均值分别为（1.34±0.09）g/cm3、(7.60±0.47)、(6.02±2.94) g/kg、(1.21±0.16) g/kg、(53.42±9.67)mg/kg、(0.42±0.14) g/kg、(6.55±2.82) mg/kg，其中有机质的变异系数最大，其次为有效磷和全磷。左岸消落带土壤pH、有机质、全氮和有效氮含量均值低于右岸，但左岸土壤全磷和有效磷含量高于右岸。淹没时间和土壤有效磷含量对消落带植物重要值影响较大。 |
| 英文摘要: |
| Hydrological regime is a main driver of plant community succession in riparian zones. Soil that has been influenced by hydrology also affects the overlying vegetation. The goal of this study was to determine the effects of periodic submergence on the habitat and vegetation in the fluctuation zone of Three Gorges Reservoir after the five years of water-level fluctuation, since impoundment first reached 175m in 2010. The characteristics of vegetation and physical-chemical properties of soil in the water level fluctuation zone of the Wanzhou region of Three Gorges Reservoir were investigated from August 17 to September 2, 2015. Eight sampling sites were selected on the main stem of the Yangtze River and its tributaries. A total of 96 plots were set within twenty-four sampling belts (10m×30m) established at three elevations： 145-155m, 156-165m and 166-175m. The height, cover and biomass of each plant in the sampling plots were determined and soil samples were collected at each sampling belt for analysis of pH, soil organic matter (SOM), total nitrogen (TN), available nitrogen (AN), total phosphorus (TP) and available phosphorus (AP). A total of 51 vascular plants species, belonging to 47 genera and 22 families, were recorded in the water level fluctuation zone of the Wanzhou section, with abundant species of Gramineae, Asteraceae, Polygonaceae and Cyperaceae. Vegetation was dominated by herbaceous plants, and the annual herbs and perennial herbs accounted for 58.8% and 27.5% of the plant community. The dominant plant species varied with elevation. Plant species with high importance values included Cynodon dactylon, Echinochloa crusgalli var. mitis and Eclipta prostrate at 145-165 m and Setaria viridis, Bidens pilosa and Cynodon dactylon at 166-175 m. The fresh weight of plants was highest in the 156-165m elevation belt at 2199.1±863.9 g/m2. The Shannon-Wiener diversity index and the Pielou evenness index were highest in the 166-175m elevation belt, averaging (2.00±0.30) and (0.85±0.06). Fresh weight and total coverage of vegetation declined with increasing slope. The species number was richest in the slope range 6o-15o. The average fresh weight, height, Shannon-Wiener diversity index and Pielou evenness index of the plant community on the left bank were higher than those on the right bank. The soil physical-chemical characteristics exhibited obvious spatial heterogeneity. The mean value and standard deviation of soil density, pH, SOM, TN, AN, TP and AP were, respectively, (1.34±0.09)g/cm3, (7.60±0.47), (6.02±2.94) g/kg, (1.21± 0.16) g/kg, (53.42±9.67) mg/kg, (0.42±0.14) g/kg, (6.55±2.82) mg/kg. The variation coefficient of SOM was the highest, followed by AP and TP. The average pH, SOM, TN and AN on the left bank were lower than those on the right bank. The importance value of species was also found to be significantly affected by submergence time and available phosphorus. |
| 张志永,程郁春,程丽,万成炎,李金波.2016.三峡库区万州段消落带植被及土壤理化特征分析[J].水生态学杂志,37(2):24-33. |
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